ON THE RELATIONSHIP OF THE INTRAPLATE DEFORMATION AND THE SECONDARY FORMATION OF OIL/GAS POOLS——THE GENERAL REGULARITIES OF THE OIL/GAS FORMATION IN MARINE ENVIRONMENT OF THE YANGTZE AREA

A systematic theory centred by the linkage of intraplate deformation and the secondary formation of oil/gas pools in later stages is proposed through the "7th Five Year National Plan Project" OIL/GAS ASSESSMENT AND GEOLOGICAL STUDIES THROUGHOUT THE YANGTZE AREA. It consists of the following principals: 1. Under the guidance of the mobilism as the fundamental recent geo-science, the evolution models of the geodynamics throughout both the Yangtze Area and completed geological history have been established. Based on the analysis of the severe tectonic reworks by intra-continental mountain-chain buildings of the area in details, the stable regions such as the Sichuan, Central Hubei, Northern Jiangsu-Southern Yellow Sea, have been suggested as the favourable areas for oil/gas exploration. 2. As viewed from plate boundary and unhomogeneous lithsphere of the Yandtze Plate, a concept of "intracontinental mountain-chain" characterized intra-continental subductions has been put forward. This is a fold-thrusting zone with obvious orientations attributed to the orogenic system of the Tethys collisions and its front belt is the major play for oil/gas accumulation of the Yangtze Area. 3. Through the analysis of the typical oil/gas pools in the area, a concept of secondary formation of oil/gas pool is proposed with the following kernels: the phase transformation of oil/gas, solution-release and multiple sources for hydrocarbon. Therefore, the oil/gas prospects in the area have been defined unequivocally. 4. The assemplage of oil/gas pools in the area is outlined as the follows: effective oil/gas sources(S),reservior space(R), trap(T), seal(S), and the time(T)for oil/lgas formation. These understandings not only sum up the regularities of the formation for oil/gas pools in marine environment of the Yangtze Area, but also fill in gaps in the modes of consideration and methodology for oil/gas exploration in rather complex structural regions.